Kinetic experiments of gas generation for typical samples of marine gas precursors including low-maturity kerogen,residual kerogen and oil as well as dispersed liquid hydrocarbon(DLH)in source rocks were performed by ...Kinetic experiments of gas generation for typical samples of marine gas precursors including low-maturity kerogen,residual kerogen and oil as well as dispersed liquid hydrocarbon(DLH)in source rocks were performed by closed system,and the evolution trends of molecular and isotopic compositions of natural gases from different precursors against the maturity(R0%)at laboratory conditions were analyzed.Several diagrams of gas origin were calibrated by using the experimental data.A diagram based on the ratio of normal and isomerous butane and pentane(i/nC4-i/nC5)was proposed and used to identify the origins of the typical marine natural gases in the Sichuan Basin and the Tarim Basin, China.And the maturities of natural gases were estimated by using the statistical relationships between the gaseous molecular carbon isotopic data and maturities(δ13C-R 0 %)with different origins.The results indicate that the molecular and isotopic compositions of simulated gases from different precursors are different from each other.For example,the dryness index of the oil-cracking gas is the lowest;the dryness indices of gases from DLH and kerogen in closed system are almost the same;and the dryness index of gases from residual kerogen is extremely high,indicating that the kerogen gases are very dry;the contents of non-hydrocarbon gases in kerogen-cracking gases are far higher than those in oil-cracking and DLH-cracking gases.The molecular carbon isotopes of oil-cracking gases are the lightest,those of kerogen in closed system and GLH-cracking gases are the second lightest,and those of cracking gases from residual kerogen are the heaviest.The calibration results indicate that the diagrams of ln(C1/C2)-ln(C2/C3)andδ13C2-δ13C3-ln(C2/C3)can discriminate primary and secondary cracking gases,but cannot be used to identify gas origin sources,while the diagram of i/nC4-i/nC5 can differentiate the gases from different precursors.The application results of these diagrams show that gas mixtures extensively exist in China,which involved the ga展开更多
The Pb, Sr isotopic compositions in organic matters (kerogen and soluble organic matter) of Lower Tertiary hydrocarbon source rock in Liaohe Fault Depression is first reported. There is a great variable rang of Pb iso...The Pb, Sr isotopic compositions in organic matters (kerogen and soluble organic matter) of Lower Tertiary hydrocarbon source rock in Liaohe Fault Depression is first reported. There is a great variable rang of Pb isotopic compositions in kerogen, 206Pb/204Pb = 17.488-18.656, 207Pb/204Pb= 15.388-15.692, 208Pb/204Pb = 37.656-37.484. And soluble展开更多
The late progress of the research on Precambrian organic matter in biomarkers, isotopes and relative analytical techniques is reviewed. The key problems in the research of Precambrian organic matter, such as indigenou...The late progress of the research on Precambrian organic matter in biomarkers, isotopes and relative analytical techniques is reviewed. The key problems in the research of Precambrian organic matter, such as indigenous test of soluble organic matter, are also discussed. At the end, the further work upon Precambrian organic matter is suggested.展开更多
Recently, using about 2100 analyzed data which are from all of major petroleum provinces and areas in China(Table 1, Fig. 1), we have studied the characteristics of the composition of carbon isotopes in the kerogens, ...Recently, using about 2100 analyzed data which are from all of major petroleum provinces and areas in China(Table 1, Fig. 1), we have studied the characteristics of the composition of carbon isotopes in the kerogens, extracts and crude oils from the whole Phamerozic(including Sinian)in China.展开更多
This study investigated the geochemical features of the lower Paleozoic strata of Yaerdang Mountain outcrop along with the core samples from well TD2∈ in the eastern Tarim Basin,NW China.The total organic carbon abun...This study investigated the geochemical features of the lower Paleozoic strata of Yaerdang Mountain outcrop along with the core samples from well TD2∈ in the eastern Tarim Basin,NW China.The total organic carbon abundance,hydrocarbon-generating precursor biospecies,and stable isotope ratios of organics and carbonate（δ13Cker,δ13Ccarb and δ18Ocarb） were comprehensively studied for their possible correlative constraints during sedimentary evolution.The results revealed that the δ13Cker（VPDB） of Cambrian kerogens along the outcrop section varied from-34.6‰ to-28.4‰,indicating an increasing tendency from the lower Cambrian to the upper Cambrian.This was on the whole accompanied by the variation in the δ13Ccarb and δ18Ocarb along the profile,which might be associated with the changes in the sea level and also in the compositional variation of benthic and planktonic biomass.The large variation in the stable carbon isotope ratios up to 6‰ along the outcrop section reflected the heterogeneity of the Cambrian source rocks from the eastern Tarim Basin.Hence,the 13C-enriched crude oils from well TD2∈might have been derived from a localized stratum of Cambrian source rocks.The results from this study showed the possibility of multiple source kitchens in the Cambrian-lower Ordovician portion of Tarim Basin.展开更多
基金the National Basic Research Program of China(Grant No.2007CB209501,2001CB209101)Knowledge Innovation Project of the ChineseAcademy of Sciences(Grant No.KZCX2-YW-108,KZCX3-SW-224)
文摘Kinetic experiments of gas generation for typical samples of marine gas precursors including low-maturity kerogen,residual kerogen and oil as well as dispersed liquid hydrocarbon(DLH)in source rocks were performed by closed system,and the evolution trends of molecular and isotopic compositions of natural gases from different precursors against the maturity(R0%)at laboratory conditions were analyzed.Several diagrams of gas origin were calibrated by using the experimental data.A diagram based on the ratio of normal and isomerous butane and pentane(i/nC4-i/nC5)was proposed and used to identify the origins of the typical marine natural gases in the Sichuan Basin and the Tarim Basin, China.And the maturities of natural gases were estimated by using the statistical relationships between the gaseous molecular carbon isotopic data and maturities(δ13C-R 0 %)with different origins.The results indicate that the molecular and isotopic compositions of simulated gases from different precursors are different from each other.For example,the dryness index of the oil-cracking gas is the lowest;the dryness indices of gases from DLH and kerogen in closed system are almost the same;and the dryness index of gases from residual kerogen is extremely high,indicating that the kerogen gases are very dry;the contents of non-hydrocarbon gases in kerogen-cracking gases are far higher than those in oil-cracking and DLH-cracking gases.The molecular carbon isotopes of oil-cracking gases are the lightest,those of kerogen in closed system and GLH-cracking gases are the second lightest,and those of cracking gases from residual kerogen are the heaviest.The calibration results indicate that the diagrams of ln(C1/C2)-ln(C2/C3)andδ13C2-δ13C3-ln(C2/C3)can discriminate primary and secondary cracking gases,but cannot be used to identify gas origin sources,while the diagram of i/nC4-i/nC5 can differentiate the gases from different precursors.The application results of these diagrams show that gas mixtures extensively exist in China,which involved the ga
文摘The Pb, Sr isotopic compositions in organic matters (kerogen and soluble organic matter) of Lower Tertiary hydrocarbon source rock in Liaohe Fault Depression is first reported. There is a great variable rang of Pb isotopic compositions in kerogen, 206Pb/204Pb = 17.488-18.656, 207Pb/204Pb= 15.388-15.692, 208Pb/204Pb = 37.656-37.484. And soluble
文摘The late progress of the research on Precambrian organic matter in biomarkers, isotopes and relative analytical techniques is reviewed. The key problems in the research of Precambrian organic matter, such as indigenous test of soluble organic matter, are also discussed. At the end, the further work upon Precambrian organic matter is suggested.
文摘Recently, using about 2100 analyzed data which are from all of major petroleum provinces and areas in China(Table 1, Fig. 1), we have studied the characteristics of the composition of carbon isotopes in the kerogens, extracts and crude oils from the whole Phamerozic(including Sinian)in China.
基金financially supported by the National Natural Science Foundation of China(Grant No.41272149)the CNPC-CAS strategic cooperation project(No.RIPED-2015-JS-255)
文摘This study investigated the geochemical features of the lower Paleozoic strata of Yaerdang Mountain outcrop along with the core samples from well TD2∈ in the eastern Tarim Basin,NW China.The total organic carbon abundance,hydrocarbon-generating precursor biospecies,and stable isotope ratios of organics and carbonate（δ13Cker,δ13Ccarb and δ18Ocarb） were comprehensively studied for their possible correlative constraints during sedimentary evolution.The results revealed that the δ13Cker（VPDB） of Cambrian kerogens along the outcrop section varied from-34.6‰ to-28.4‰,indicating an increasing tendency from the lower Cambrian to the upper Cambrian.This was on the whole accompanied by the variation in the δ13Ccarb and δ18Ocarb along the profile,which might be associated with the changes in the sea level and also in the compositional variation of benthic and planktonic biomass.The large variation in the stable carbon isotope ratios up to 6‰ along the outcrop section reflected the heterogeneity of the Cambrian source rocks from the eastern Tarim Basin.Hence,the 13C-enriched crude oils from well TD2∈might have been derived from a localized stratum of Cambrian source rocks.The results from this study showed the possibility of multiple source kitchens in the Cambrian-lower Ordovician portion of Tarim Basin.
